Pitman arms

[glider_6969]

Can someone tell me what the difference is between the pitman arm from a manual steering box and the one for a power steering box? I have both boxes on my bench, the one from my 68 and the one I want to use can be found in 80-85 trucks, and comparing or trying to figure out why I can't use the stock pitman arm from the manual box. Both boxes have the nut that holds the arm on to the shafts that seem to be the same size.....

what am I missing... any help would be great thanks.

[lolife99]

My books show 2 different part numbers.
I wonder if it's the spline of the steering box shaft, or the size/taper of the end that connects to the centerlink?

[lilpoindexter]

The splines are different...I think they did them that way, so they couldn't bolt on to wrong box at the factory.

[glider_6969]

If I could get the pitman arm (nut) off of the manual one I pulled I would be able to check the splines, I'll have to go to my buddies and use the torch and get some heat on it.. thanks guys.